The long line of representation studies posits that proportional representation systems, with larger electoral districts, have a representational advantage over majoritarian systems. However, over the last decade, scholars have challenged this longstanding nding (Blais & Bodet 2006, Golder & Stramski 2007). Additionally, Golder & Stramski (2007) initiated a debate over the conceptualization and measurement of congruence, arguing that the most common practice of assessing congruence is flawed. They call for an improved measure of congruence. In the light of this recent debates, the purpose of this thesis is to inspect the relationship between institutional designs and political representation in the European context, using Voting Advice Application generated data. Three main research questions are explored. The first question relates to institutional designs such as district magnitude, and electoral system characteristics such as disproportionality or polarization, investigating the conditions necessary for a country to present high levels of congruence between its citizens and their representatives. Looking at party level characteristics, I will investigate what are the effects of niche party status and governmental status on issue congruence in European democracies? Last but not least, what is the role of individual characteristics? These questions will be addressed by studying the impact of different features of electoral systems, party and individual characteristics have on political representation conceptualized as issue congruence. Congruence is measured as the degree of matching of the common policy preferences of citizens and parties as indicated by the Voting Advice Applications EU Pro filer 2009 and EUvox 2014. The present work contributes to the stream of research on political representation understood as congruence. The strength of this work lays in its comparative approach, and the use of VAA generated data to measure congruence. While most of the studies on political representation using congruence focus on the Left-Right dimension, this thesis uses the concept of issue congruence. Based on the 28 common statements of the VAA tool, the measure of congruence is metric-free, allowing for cross-country comparisons. Although there is a wide range of research on the effects of electoral systems on political representation, most of these studies are limited in their use of comparative approaches. The lack of extensive comparative research on issue congruence is due to insufficient data. The 2009 EU Profi ler and 2014 EUvox address this issue, providing the necessary framework for testing the predictors of congruence at a system, party and individual level. Political representation can be operationalized through congruence, as the distance between the citizen and the representative (Huber & Powell 1994, Powell 2004). Issue congruence is the correspondence between party electorates and their representatives across a set of salient policy dimensions (Powell 2004). VAA generated data provides a new means of measuring congruence. I propose two new measures of congruence, based on the distance between the citizen and the party the citizen intends to vote for. Unlike other comparative studies that measure congruence with the help of the Left-Right scale, the present work focuses on issue policies. Issue congruence is the outcome of the match between the citizen and the party she intends to vote for on a series of 28 and 22 political statements. Additionally, the focus on issue congruence is important because issue representation is mostly inferred from the alternative interpretations of congruence. The measures of issue congruence therefore contribute to a better understanding of political representation in the EU political space, tackling the recurrent crisis of representation.

Les Systèmes d’Aide au Vote (SAV) comparent, sur des enjeux variés, les positions des utilisateurs avec celles des partis ou des candidats qui sont établies à partir d’une analyse de contenu de leur programme électoral. Les SAV sont un outil d’analyse novateur à usage des politistes puisqu’ils leur permettent de récolter des données empiriques à grande échelle tout au long d’une campagne électorale. L'objectif principal de cette thèse est d'utiliser les données collectées par les SAV afin d’analyser la diffusion d’un site Web à caractère informatif et politique, i.e. les SAV, auprès des internautes dans des systèmes médiatiques différents. Cette thèse teste l'hypothèse selon laquelle l'utilisation des SAV par différents groupes d'électeurs (électeurs partisans, hésitants et indécis) varie selon les systèmes médiatiques. Les analyses des données collectées par des SAV dans sept démocraties électorales représentant trois différents types de systèmes médiatiques (Democratic Corporatist, Liberal et Pluralist Polarized) montrent que les systèmes médiatiques structurent les comportements et influent sur le degré d’exposition à des informations politiques en ligne. Le second apport de cette thèse est l’utilisation des données collectées par un SAV pour l'analyse électorale, notamment pour l’étude du vote sur enjeux et des dynamiques de campagne. Plusieurs analyses sont réalisées dans cette thèse à partir des données recueillies par le SAV français de La Boussole présidentielle. Cette thèse montre que, bien qu’étant non-probabilistes, les échantillons SAV sont très informatifs à condition d’être intégrés dans un cadre de recherche approprié et d’ajuster les biais statistiques. / Online Voting Advice Applications (VAAs) are websites or online applications that show voters which party or candidate is closest to their own political ideas based on how they mark their positions on an ample range of policy issues. In addition to providing voters with reliable information in a structured manner, VAAs are an innovative data-collection tool on issue positions and on a wide set of other indicators. The main scope of this dissertation is to use VAA-collected data to learn about online information exposure during campaigns across media systems. Building on the realistic view of the Web’s political potential and its impact on the public, this dissertation test the hypothesis that VAA use by different voter groups (partisan, doubting and undecided voters) varies across media systems. The analyses of VAA-collected data in seven electoral democracies across three different types of media systems (Democratic Corporatist, Liberal, and Polarized Pluralist) show that media systems are key mediators to explain online information exposure. The second scope of this dissertation is to use VAA-collected data for the sake of electoral analysis, in particular to study issue-voting and campaign dynamics analyses. Several analyses are carried out using data collected by the French VAA of La Boussole présidentielle. This dissertation shows that, despite being non-probabilistic, VAA samples can serve as a very informative tool for the study of political and communication processes during electoral campaigns if integrated within an appropriate research framework and with the use of proper statistical adjustment.

This thesis treats of the usage of online voting advice applications, VAA, by Swedish students at the Linnaeus university. Four questions are investigated: 1) to what extent do the students use VAA? 2) do they follow the results? 3) are there any differences between groups? and finally 4) how do they reflect upon the VAA? The thesis is based on a theory of electoral democracy where the elections and the voters are the focal point. The voters’ volatility is also theorised and put in connection with VAA. A survey is used to answer questions 1–3 and semi-structured interviews to answer question 4. The main findings are that a remarkable part of the Linnaeus students, 62 %, use VAA and the applications are mainly used by the young. A substantial part also seems to follow the results presented by the application, above all the students that took the VAA seriously. 14 % of the students based their vote exclusively on VAA results. The students find positive and negative aspects to the use of VAA. They can be used for fun or be developing for the users. They should however only be used as a complement; the students point out that more information is needed to base the vote on. By informing the voters, the Linnaeus students think that VAA can mobilise voters and change their preferences.